The creationists are howling. McBride’s evisceration, with Carl Zimmer’s detailed description of the evidence for chromosome fusion, all discrediting what they thought would be a hot new text on the scientific evidence for creation, has made them so furious that they’re even lashing out at me in email — I just linked to the evidence, so I imagine Zimmer and McBride must be seeing some entertaining spectacles in their inboxes. I do so love to see the creationists dancing in the flames of their own immolation.

I will say this, though: I did get one very polite email from a creationist, who told me that he was not a scientist, but that he’d read a couple of articles that sounded impressively sciencey to him, and asked if they didn’t represent a legitimate criticism of the chromosome fusion idea? And he very nicely sent along the two papers for me to read. Here they are:

Two things jumped out at me: it’s by batty Jerry Bergman, no credible source at all, and it’s published in the inbred in-house journal of the Institute for Creation Research. These are not legitimate science papers, although they do throw around enough science terms and techniques, and follow the form of a real science paper, to generate confusion in the mind of the naive reader. They’re beautiful examples of cargo cult science by creationists. Would you like to read them, or use them as bad examples? Here you go, download it for entertainment purposes only.

I read them anyway. I’m not going to bother with a detailed refutation, but I’ll give you the gist. The fundamental confusion in both papers is the nature of the evidence for an ancestral chromosome fusion, and a focus on irrelevant details that are not central to the argument.

The story is this. At some time after the separation of the human and chimpanzee lineages, two ancestral chromosomes, #12 and #13 in the chimpanzee, fused end-to-end to form a single chromosome, #2, in humans. Chimpanzee chromosome 13 forms the short arm (2p) and part of the long arm (2q) of human chromosome 2, while chimpanzee chromosome 12 forms most of the long arm (2q) of chromosome 2.

The primary evidence for this fusion is the comparative genetic content of these chromosomes. That is, most of the genes in chimpanzee chromosome 13 are found in human 2p, and most of the genes in chimpanzee chromosome 12 are in human 2q. The chromatin binding patterns line up, the sequence analysis confirms, and there have been some lovely FISH studies that show the correspondence.

What has since been done is that a prediction was made that there ought to be fragments of telomeres (the end caps of chromosomes) in the middle of chromosome 2, at the fusion site. Which has been examined. And the prediction has been confirmed.

Bergman and Tomkins ignore every single bit of that. Instead, what they do is focus on just the region of the fusion, and complain that it is a tangled mess and hard to interpret — that it is a degenerate telomeric region, rather than a complete and intact telomere, which is what they demand be present. This is an unrealistic expectation, given that every paper on the structure of the fusion region makes the point that it is degenerate.

An analogy: imagine a red Ford Mustang and a blue BMW X6 are in a head-on collision, and both have totally wrecked front ends, with bumpers and radiators and headlights interlocked and everything about their grilles in tangled confusion, and with bits and pieces torn loose and flung about. You’d be able to look at the crash and still tell by everything in and behind the engine compartment that Car #1 was a Mustang and Car #2 was an X6.

Bergman and Tomkins are the bewildered and incompetent investigators who ignore every other factor in the crash, look at a few particularly mangled bits of the wreckage, and declare that they can’t identify it, therefore…the two vehicles were assembled at the factory in this particular configuration, and no crash occurred. But they use lots of sciencey language to explain this at tendentious length, which is sufficient to convince non-scientists that the interpretation of an obvious historical event has been refuted. And that’s all they need to do to accomplish their goals: fling about unfounded fear, uncertainty, and doubt to win over the ignorant.